How We Built Our Stack for Shipping at Scale

I'm not sure how to best characterize it in the very beginning (and I wasn't there) but in the 3.5 years I've been here it has largely been smaller services -- even down to things like the app's nav is its own service. More recently I think we've really embraced microservices (the number of deployables has grown ~2x in the last year).

Personally I think after 5 (and definitely 10) engineers working on a single app I would look at whether you can break it down into independent services.

About 25 plus or minus.

teams are typically ~3 engineers, working with a Product Manager and a Product Designer

Personally I've been a fan as it aligns incentives for developers to care deeply about code quality/stability/etc. YMMV if not working on a SaaS product where build/deploy is measured in just a few minutes.

We've invested in a mix of both automated testing, of course, and a lot of monitoring/alerting/tracing to detect problems quickly. That can act as a safety net for deploying frequently that problems will be caught early and can be corrected (rollback or fix & roll-forward).

I'm a fan of saying we've chosen to optimize for MTTR instead of MTBF.